The invention is based on a fuel injection apparatus for internal combustion engines. In a fuel injection apparatus of this kind known from German Offenlegungsschrift 31 18 669, the fuel injection quantity that has been pre-stored in a pump work chamber is determined by the duration of the opening period of an electronically actuatable metering valve, and a shift in the instant of supply onset is attained, and controlled in accordance with operating characteristics, by means of a variation in the return-flow fuel quantity. This return-flow fuel quantity is adjustable by means of the controlled rotational position of the pump piston, which is provided with an oblique control edge, and in any event the pump work chamber is refilled prior to the next subsequent injection stroke. The refilling process is reinforced by a fuel reservoir that is connectable with the pump work chamber. Because of the variable volume of the fuel during its diversion and refilling, and because each operation takes place at a completely different pressure level, influences on the onset of injection and on the supply quality arise in the known fuel injection apparatus which must be compensated for in the electric control unit by mean of appropriate correction values. It is thus an object of the invention to improve the fuel injection apparatus such that the variable fuel volume during diversion and refilling does not have a disadvantageous effect on the accuracy of the controlled fuel injection quantity and the instant of supply onset. Further, the smallest possible idle volume in the vicinity of the inflow and return-flow conduit, additional errors that would be caused by escaping leaking fuel and impairments in fatigue strength that would be caused by cavitation and strains in the vicinity of the cylinder bore, the metering valve and the refill reservoir are prevented.